CGS System of Units
Easily convert CGS units to SI: cm to m, g to kg, dyn to N, erg to J, Ba to Pa, P to Pa·s. Free online converter for physics, science, and engineering.
About This Calculator
The CGS System of Units Converter instantly converts physical quantities from the centimeter-gram-second (CGS) system to the International System of Units (SI) and other common unit systems. This converter supports seven physical quantities: length (centimeters to meters), mass (grams to kilograms), force (dynes to newtons), energy (ergs to joules), pressure (baryes to pascals), dynamic viscosity (poise to pascal-seconds), and kinematic viscosity (stokes to square meters per second). It is an essential tool for physics students, educators, researchers, and engineers who work with historical scientific literature or specialized fields that still use CGS conventions.
The CGS system was first proposed in 1832 by the German mathematician Carl Friedrich Gauss and was later extended by the British Association for the Advancement of Science in the 1870s. While SI has become the international standard, CGS units persist in several scientific domains. In astrophysics, the erg and dyne remain common. In electromagnetism, the Gaussian and Lorentz-Heaviside variants of CGS are still used. The conversion factors between CGS and SI are straightforward powers of 10 for base quantities: 1 cm = 0.01 m, 1 g = 0.001 kg, and derived units follow accordingly. For example, 1 dyne = 1 g·cm/s² = 10⁻⁵ kg·m/s² = 10⁻⁵ N, and 1 erg = 1 g·cm²/s² = 10⁻⁷ kg·m²/s² = 10⁻⁷ J.
Regional Notes
India (IN): SI units are the legal standard for all scientific, educational, and commercial measurements. The CGS system is taught in physics curricula primarily for historical context and in certain specialized topics like surface tension (dyne/cm) and viscosity (poise).
United States (US): SI units are used in scientific research and education, while US customary units dominate everyday and industrial use. CGS units may be encountered in academic physics contexts, particularly in mechanics and electromagnetism textbooks.
United Kingdom (UK): SI units are the official measurement standard. CGS units appear in physics education and in older scientific publications. The poise and stokes remain common in fluid dynamics research and industrial viscosity measurement.
Frequently Asked Questions
What is the CGS system of units?
The CGS (centimeter-gram-second) system is a metric system of measurement where the base units are the centimeter for length, the gram for mass, and the second for time. It was introduced in the 19th century and is still used in many branches of physics, particularly astrophysics, electromagnetism, and mechanics, though the SI system has largely replaced it for most scientific work.
How do I convert centimeters to meters?
To convert centimeters (cm) to meters (m), divide by 100. For example, 150 cm ÷ 100 = 1.5 m. Conversely, multiply meters by 100 to get centimeters. The CGS base unit for length is the centimeter, while the SI base unit is the meter.
How do I convert grams to kilograms?
To convert grams (g) to kilograms (kg), divide by 1000. For example, 500 g ÷ 1000 = 0.5 kg. The CGS base unit for mass is the gram, while the SI base unit is the kilogram.
What is the conversion from dyne to newton?
One dyne (dyn) equals 10⁻⁵ newtons (N). The dyne is the CGS unit of force defined as the force needed to accelerate a mass of one gram at a rate of one centimeter per second squared. The newton is the SI unit, representing the force needed to accelerate one kilogram at one meter per second squared.
How many ergs are in one joule?
One erg equals 10⁻⁷ joules (J). The erg is the CGS unit of energy defined as the work done by a force of one dyne over a distance of one centimeter. The joule is the SI unit of energy, equivalent to the work done by a force of one newton over a distance of one meter.
What is the barye and how does it relate to the pascal?
The barye (Ba) is the CGS unit of pressure, equal to one dyne per square centimeter. One barye equals 0.1 pascals (Pa). The pascal is the SI unit of pressure and is defined as one newton per square meter.
What are poise and stokes in the CGS system?
The poise (P) is the CGS unit of dynamic viscosity, equal to one gram per centimeter per second. One poise equals 0.1 pascal-seconds (Pa·s) in SI. The stokes (St) is the CGS unit of kinematic viscosity, equal to one square centimeter per second. One stoke equals 10⁻⁴ square meters per second in SI.
Is this CGS converter free to use?
Yes, all calculators on Calculy are completely free to use with no registration or hidden fees. You can perform unlimited CGS to SI conversions across all supported physical quantities.